A number of touch fastening systems, such as those found in personal care and other products, feature arrays of discrete hooking structures that extend from a common base. Many such products are formed from resin, such as by molding the base and hooking structures from a unitary resin flow, or severing the rails of a plastic extrusion, or by molding the base with preform structures (e.g., straight stems) that are later deformed to create hooking structures. Some hooking structures are hook-shaped, with tips that extend in a primary lateral direction to define a crook. Some hooking structures have multiple crooks, with an example being a ‘palm tree’ structure with tips extending in two opposite directions. Some hooking structures are known as ‘mushroom-type’ and feature engaging heads that overhang the base all around a supporting stem.
Molding overhanging heads in non-opening cavities requires selecting a resin and a hooking element shape that will allow the molded elements to temporarily deform while being withdrawn from the mold, and that will also provide a desired level of peel resistance during use.
Improvements are continuously sought to facilitate the manufacture of fastener products with desired properties, including peel and shear strength and touch softness.